From 176d11690ba2c8ad59f99734d692f19f451c408b Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 28 Dec 2015 19:23:00 +0900 Subject: [PATCH] clk: move core->parents allocation to clk_register() Currently, __clk_core_init() allows failure of the kcalloc() for the core->parents. So, clk_fetch_parent_index() and __clk_init_parent() also try to allocate core->parents in case it has not been allocated yet. Scattering memory allocation here and there makes things complicated. Like other clk_core members, allocate core->parents in clk_register() and let it fail in case of memory shortage. If we cannot allocate such a small piece of memory, the system is already insane. There is no point to postpone the memory allocation. Also, allocate core->parents regardless of core->num_parents. We want it even if core->num_parents == 1 because clk_fetch_parent_index() might be called against the clk_core with a single parent. If core->num_parents == 0, core->parents is set to ZERO_SIZE_PTR. It is harmless because no access happens to core->parents in such a case. Signed-off-by: Masahiro Yamada Reviewed-by: Vladimir Zapolskiy Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 51 ++++++++++++++++++----------------------------- 1 file changed, 19 insertions(+), 32 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index f9cab0919bb4..a92feedda592 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1067,13 +1067,6 @@ static int clk_fetch_parent_index(struct clk_core *core, { int i; - if (!core->parents) { - core->parents = kcalloc(core->num_parents, - sizeof(*core->parents), GFP_KERNEL); - if (!core->parents) - return -ENOMEM; - } - /* * find index of new parent clock using cached parent ptrs, * or if not yet cached, use string name comparison and cache @@ -1718,11 +1711,6 @@ static struct clk_core *__clk_init_parent(struct clk_core *core) index = core->ops->get_parent(core->hw); - if (!core->parents) - core->parents = - kcalloc(core->num_parents, sizeof(*core->parents), - GFP_KERNEL); - ret = clk_core_get_parent_by_index(core, index); out: @@ -2361,26 +2349,15 @@ static int __clk_core_init(struct clk_core *core) __func__, core->name); /* - * Allocate an array of struct clk *'s to avoid unnecessary string - * look-ups of clk's possible parents. This can fail for clocks passed - * in to clk_init during early boot; thus any access to core->parents[] - * must always check for a NULL pointer and try to populate it if - * necessary. + * clk_core_lookup returns NULL for parents that have not been + * clk_init'd; thus any access to clk->parents[] must check + * for a NULL pointer. We can always perform lazy lookups for + * missing parents later on. */ - if (core->num_parents > 1) { - core->parents = kcalloc(core->num_parents, - sizeof(*core->parents), GFP_KERNEL); - /* - * clk_core_lookup returns NULL for parents that have not been - * clk_init'd; thus any access to clk->parents[] must check - * for a NULL pointer. We can always perform lazy lookups for - * missing parents later on. - */ - if (core->parents) - for (i = 0; i < core->num_parents; i++) - core->parents[i] = - clk_core_lookup(core->parent_names[i]); - } + if (core->parents) + for (i = 0; i < core->num_parents; i++) + core->parents[i] = + clk_core_lookup(core->parent_names[i]); core->parent = __clk_init_parent(core); @@ -2578,12 +2555,20 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) } } + /* avoid unnecessary string look-ups of clk_core's possible parents. */ + core->parents = kcalloc(core->num_parents, sizeof(*core->parents), + GFP_KERNEL); + if (!core->parents) { + ret = -ENOMEM; + goto fail_parents; + }; + INIT_HLIST_HEAD(&core->clks); hw->clk = __clk_create_clk(hw, NULL, NULL); if (IS_ERR(hw->clk)) { ret = PTR_ERR(hw->clk); - goto fail_parent_names_copy; + goto fail_parents; } ret = __clk_core_init(core); @@ -2593,6 +2578,8 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) __clk_free_clk(hw->clk); hw->clk = NULL; +fail_parents: + kfree(core->parents); fail_parent_names_copy: while (--i >= 0) kfree_const(core->parent_names[i]); -- 2.30.2